Fig. 4

Inexact adaptation in ramp stimuli. A range of circuits may exhibit inexact adaptation in a ramp such as (a) A feedback motif (MA09.FB), where an increase of feedback strength brings steady state output closer to pre-stimulus value. (b) A feedforward motif (MA09.FB) with saturation (c) Another feedforward motif (CO09.M1). Here due to thresholds in one feedforward leg, the steady state reaches 0. (d) The location at which a signal appears in a motif can be of great importance: shown are two different locations of signal appearing in model DR08.M33, one resulting in exact adaptation and the other, a nonadaptive response. In contrast to the previous cases, the non-adaptive behaviour here is not due to saturation, and the steady state carries information about the gradient of the ramp (see text)